DonutFeb 4, 2020

Well, you might have noticed it's two different apps. File manager belongs to OnePlus while Files is a Google app. Files also kinda replaced the Downloads app.​

it doesn't seems to be a Google app. it has a different icon(refer to the attachment) i doubt it's automatically installed, as when I'm clicking on app link it shows as "item not found"
above screenshot is of pre-installed app details